PROJECT SUMMARY The proportion of the elderly people (e65 years) has continued to increase among over half a million Americans with end-stage renal disease (ESRD). In 1990, 2000 and 2010, 39%, 44% and 44% of all prevalent dialysis patients, and 4%, 10% and 20% of all kidney transplant recipients were elderly. Consequent to the absolute increase of elderly individuals in the population pyramid, the prevalence and incidence of ESRD have also risen. Kidney transplantation is generally regarded as the treatment of choice in ESRD irrespective of age. However, there are no comparative data about the best choice of renal replacement therapy for the elderly ESRD patients, in whom such novel and fast-growing dialysis modalities as nocturnal and home hemodialysis (HHD) may offer same or even better survival advantages than deceased donor transplantation, the most common kidney transplantation in the elderly. Previous data suggest that the projected increases in life spans in transplant patients compared to conventional dialysis were 2.8 and 1.1 years for patients aged 65-69 and 70-74 years, respectively. Some recent studies show no difference in the adjusted survival between nocturnal HHD and deceased donor transplantation irrespective of age. We hypothesize that such contemporary dialysis treatments as HHD are associated with greater survival than deceased donor transplantation in most transplant-wait-listed elderly ESRD patients without a living donor and that a scoring system based on demographic and other recipient clinical and laboratory data can identify those elderly ESRD patients in whom such dialysis modalities are more or less advantageous. In this project, we will obtain, refine, and link data from DaVita, one of the nation's largest dialysis providers, with a national transplant database known as the Scientific Registry of Transplant Recipients (SRTR). We will then study approximately 1,000 elderly (>65 years) incident HHD patients who started dialysis therapy in a DaVita clinic between 1/2007 and 12/2011 (5 years) and after merging their data with the SRTR database to create a propensity score matched (1:4) cohort of elderly cadaveric kidney transplant recipient (n=5,000). We will also create a propensity-matched cohort with living donor kidney transplant recipient. In addition, we will develop and examine a series of predictor scores for selection of living and cadaveric kidney transplantation in ESRD recipient over 65 years of age. Our scoring tools will predict the 1-, 3- and 5-year patient and kidney allograft survival as well as graft-loss censored mortality in the elderly population. This comparative effectiveness research proposal will innovatively utilize new methodological approaches including propensity score based analyses to assess and to quantify the true effectiveness of kidney transplantation versus certain dialysis modalities including HHD. This 2-year project will efficiently generate a wealth of time-sensitive information about the potential treatment of choice in elderly ESRD patients that will be of immediate clinical and public health relevance and inform decision making by physicians, patients, providers, and payers.